Biostatistical expertise was provided to researchers from NCI and other institutions on the design and statistical analysis of a broad range of laboratory studies including: host cell reactivation studies in the Dermatology Branch, DCS, NCI, to examine blockage of transcription due to defective nucleotide excision repair of specific lesions induced by oxygen radicals in cells from patients with xeroderma pigmentosum and Alzheimer's disease; studies of survival of knockout mice with the Veterinary and Tumor Pathology Section, Animal Sciences Branch, DBS, NCI; an investigation of polymorphic variation in the XPC gene by the Laboratory of Molecular Carcinogenesis, DBS, NCI; experiments in the Molecular Genetics Section of the Laboratory of Molecular Biology, DBS, NCI, examining mutation rates in transgenic mice and wild type mice, and comparing melanoma incidence rates in different strains of transgenic mice; a study of methylation and Ras mutations in skin cancers induced in mice by initiation with DMBA and promotion with TPA or mezerein in the Laboratory of Cellular Carcinogenesis and Tumor Promotion, DBS, NCI; an investigation in the Laboratory of Molecular Genetics of the NIA evaluating mutational spectra and microsatellite instability in immunoglobulin genes in order to explore mechanisms for hypermutation; a study by the Laboratory of Molecular Genetics of the NIA measuring repair of oxidative DNA damage in brain tissue from patients with primary neurologic degenerations; a study of apoptosis rates in ARF, BAX and INK knockout mice with the Yale University Department of Therapeutic Radiology and Genetics; a study with the University of Texas Southwestern Medical Center of molecular changes in lung cancers and breast cancers following treatment for Hodgkin's disease; an investigation in the Laboratory of Human Carcinogenesis and at the University of Vermont examining evolutionary conservation of p16 mutational hot spots found in human cancers; a study by the University of Minnesota Laboratory of Environmental Medicine and Pathology of chromosome damage and hormone levels in pesticide appliers.